See the solution below with Step by Step Explanation.
Explanation:
Solution (Step by Step) :
1. Create a Service Account:
- Create a service account YAML file named 'database-service-account.yamr with the following contents:

2. Create a Secret for the API Key: - Create a secret YAML file named 'database-api-key.yaml with the following contents:

3. Create a Role and Role8inding: - Create a Role YAML file named 'database-role.yaml with the following contents:

4. Create a ROIeBinding YAML: - Create a RoleBinding YAML file named 'database-rolebinding.yamr with the following contents:

5. Apply the YAML Files: - Apply the created YAML files using 'kubectl apply -f database-service-account.yamr , 'kubectl apply -f database-api-key.yamr, ' kubectl apply -f database-role.yamr , and 'kubectl apply -f database-rolebinding.yamr 6. Update your Deployment: - Update your application deployment to use the 'database-service-account and mount the secret containing the API key.

7. Access the External Database: - Your application container should now be able to access the external database using the API key provided in the secret.